Thanks for the great question! Tikibar is right, if you were to just add a data package to one line on the account, it would be $30.00 for 2 GB of data. You can go higher as well. Keep in mind, if you have multiple phones upgrading to smartphones, you may want to take a look at our Share Everything plans here http://bit.ly/xdDajD and that may save you some money versus individual packages for each line.